More than a quarter (27%) of people are behind with at least one bill, research for Citizens Advice suggests.
Just over a fifth (21%) of people have borrowed money to pay for essentials, such as groceries, in the past six months, according to the charity.
It said that energy debts and council tax arrears are the most commonly encountered problem debt – with half (50%) of people helped by
Citizens Advice reporting one or both of these debts.
The charity said it has been dealing with increasing numbers of people with a negative budget – with more money going out than coming in.
Currently, the average person the charity helps with debt is £28 in the red at the end of the month while, four years ago, they had a surplus of £21.
Mortgage holders and people in employment are among the newer groups of people the charity said are approaching it for help.
It is helping nearly 40,000 people every month with debt issues, with those requiring help increasing 21% between the second and third quarters of 2023.
Current systems contain too many traps and hurdles for people in debt to get a fresh start, the charity said.
It added that, for example, if someone misses just one council tax payment they can become liable for a whole year’s bill, a scenario which may lead to bailiffs knocking at their door.
High levels of benefit deductions can also eat away at people’s income pushing them into debt, it said.
Citizens Advice is calling for reforms to how debt is collected and managed so that people can pay back what they owe in an affordable way.
Dame Clare Moriarty, chief executive of Citizens Advice, said: “We’re now seeing the levels of debt we feared and the picture is only set to get worse
“Millions of people are doing their best to balance the books but the numbers simply don’t add up.
“Too many people are living on empty, unable to pay their bills or even put food on the table.
“Current systems are stacked against people in debt, instead we need an approach that offers more support and realistic routes out of debt.
“We need to see reforms that will have a tangible impact.”
Citizens Advice used a survey by Walnut Unlimited among more than 4,200 people across the UK in June for part of its research.